A Narrative Review of Repository Corticotropin Injection for the Treatment of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder that affects multiple organ systems. The most prevalent manifestations include constitutional symptoms, arthritis, and rash. An SLE flare is defined as a measurable increase in disease activity that may prompt a change in treatment. According to the European Alliance of Associations for Rheumatology guidance, SLE treatments should be aimed at reducing disease activity and flares, as well as preventing organ damage. Standard-of-care treatment of SLE includes glucocorticoids, but their long-term use is associated with damage accrual. Repository corticotropin injection (RCI; Acthar(®) Gel) is a naturally sourced complex mixture of adrenocorticotropic hormone analogs and other pituitary peptides that has anti-inflammatory and immunomodulatory effects beyond its steroidogenic effect, and has been US Food and Drug Administration–approved for the treatment of SLE flares and as a maintenance therapy. This review summarizes data from three clinical trials that evaluated the efficacy and safety of RCI in the treatment of patients with moderate–severe refractory SLE. These clinical trials confirmed that RCI improved global disease activity scores and some SLE clinical manifestations. Analysis of pooled data from these trials showed that RCI treatment significantly improved the British Isles Lupus Assessment Group 2004 (BILAG-2004) index scores after 8 weeks of treatment, and tender and swollen joint counts after 4 weeks. These clinical trials demonstrated an acceptable safety profile with few serious adverse events reported. The distinct mechanisms of action from standard-of-care therapies and the favorable safety and good efficacy profiles support the use of RCI as therapy for patients with refractory SLE.